Hiding the implementation

An encapsulated design hides its implementation from the class user.

It reveals only its interface.

Listing 3 is an example of an encapsulated class:

Listing 3. Encapsulation.

class Date{ //--- Implementation is private by default int month, day, year;//private data members ...//other private data members or functions public://the class interface is made public Date(int mo,int da,int yr);//public constructor Date operator+(int n);//public overloaded operator ...//other public interface functions };// note the required semicolon